Adding apparatus.



J. W. ALEXANDER;

ADDING APPARATUS,

APPLICATION FILED MAY 11,1910.

973,905. Patented Oct. 25, 1919.

WITNESSES:

IN VE IV TOR J I V 565 171250197 ATTORNEYS UNITED STATES PATENT OFFICE.

JOHN W. ALEXANDER, 0F SPARTANBURG, SOUTH CAROLINA.

ADDING APPARATUS.

To all whom it may concern:

Be itknown that I, JOHN V. ALEXANDER, a citizen of the United States,and a resi dent of Spartanburg, in the county of Spartanburg and Stateof South Carolina, have invented an Improved Adding Apparatus, of whichthe following is a specification.

My invention is a simple educational apparatus for instruction andpractice of children in adding numerals although it may be used forpractice in subtraction, multiplication, and division.

The construction and manner of using the same are as hereinafterdescribed, and illustrated in the accompanying drawing in which- Figure1 is a face or plan view of the apparatus. Fig. 2 is a face or plan viewof a portion, showing a different adjustment of the movable blocksbearing numerals. Fig. 3 is a cross section on the line 38 of Fig. 2.Fig. 4 is a perspective view of one of the movable blocks.

The rigid frame of the apparatus is elongated and formed of two parallelupper and lower bars A and B, which are spaced apart and connected byshort end bars C. The upper bar A is inscribed with two sets of digits,1 to O, inclusive, the same being arranged in regular numerical order;and both bars are provided interiorly with lengthwise ribs or tongues a,o, as shown in Figs. 1 and 3.

A series of rectangular blocks D, ten in number and bearing digits 1 toO inclusive, is arranged in the space between the bars A and B andprovided with opposite grooves (Z, which are adapted to receive thetongues o, b, so that the blocks may slide freely thereon from left toright or right to left. The series of blocks D is of such horizontalwidth that when adjusted in consecutive order, as shown in Fig. 1, theyoccupy the same length in the frame as one of the two sets or groups ofnumerals inscribed on the bar A. The numerals on the latter areseparated from each other by transverse scores or marks, so that theymay be more easily distinguished by the pupil. By placing the slidableset of blocks D directly under the Specification of Letters Patent.

Application filed May 11, 1910.

Patented Oct. 25, 1910.

Serial No. 560,601.

first set or group of numerals on the upper bar, as shown in Fig. 1, itgives none but even combinations; thus, 1 1, 22, 3-3, etc. By moving theblocks D to the right the distance of one number or block space, we havethe combinations 1-2, 23, 3-fl-, etc; and by moving still another numberor space, we have 13, 2l, 35, etc. By adjusting the movable blocks inthis manner the space of one block at a time, until the whole series ofblocks has been moved to the right as far as the frame permits, everycombination that it is possible to form, such as 8-7, 78, 3 9, 93, etc.,will have been formed. Thus, the pupil may be practiced in addition ofthe digits until he shall have become thoroughly familiar with the sumsthat may be formed by combination of any numeral in the upper groups orsets with any in the lower or movable set.

In case the pupil is less practiced or less familiar with the sum formedby the addition of any two numerals, one of such numerals may beseparated from the others in the lower row and adjusted under thedesired number in the upper row, and thus the pupil will quickly acquireproficiency in the required addition, until all difiiculty hasdisappeared.

lVhile my invention has been described for convenience as an addingapparatus, as before indicated, it is usable in the other alliedoperations of subtraction, multiplication, and division.

What I claim is 1. An adding apparatus comprising a rigid elongatedframe having parallel upper and lower bars spaced apart and providedinteriorly with longitudinal tongues, the upper bar being inscribed withtwo sets of digits in consecutive order, and a series of blocksinscribed with digits 1 to O, inclusive, and arranged in the spacebetween said bars and adapted to slide thereon, as shown and described.

2. An adding apparatus, comprising a frame having upper and lower barsarranged parallel and spaced apart, one of said bars being inscribedwith two sets of digits, and a series of blocks inscribed with digitsand arranged between the said bars parallel with said bar, as shown anddeand adapted to slide thereon. scribed.

3. An addin a )aratus COIDPIlSlII aframe having a? lor iitudindl barinscri bed JOHN ALEXANDER with two sets of digits in consecutive order,WVit-nesses: and a series of blocks similarly inscribed LOGNA LOGAN,with digits and adapted to slide in a line i J. O. ZIMHERMAN.

